In order to carry out the practice of assessment, tools are required to mediate and
accomplish each of these four steps (Fig. 2). Observations are elicited by designed tasks,
scores are assigned with the aid of a set of scoring guides, summary measures are the result
of applying a measurement model to the individual scores, and interpretation of the
measures depends upon a model of cognition. Together, these four are the cornerstones of
any assessment instrument (Fig. 3).
This cornerstone model of assessment practice is intended to be sufficiently general to
accommodate a wide range of assessment purposes and models of cognition. The purpose
of assessment may be formative or summative and may provide information for immediate,
close, proximal, distal, or remote stakeholders (Hickey et al. 2006; Ruiz-Primo et al. 2002).
A particular model of cognition may be unidimensional or multidimensional, involve
variables that are continuous or discrete and bounded or unbounded, locate cognition within
individuals, groups, or activity systems, and represent cognitive processes ranging from
simple recall to ill-defined real-world problem solving.